The invention relates to a multiple-flow liquid ring pump.
A liquid ring pump is known from U.S. Pat. No. 4,132,504. The rotor housing has a substantially circular cross-section. Ribs of lengthwise extension, which stand out radially and which, towards the inside, define channels, are disposed on the surface, in the shape of a cylinder jacket, of the rotor housing. A drawback of this arrangement resides in that the space maximally taken by the housing of the liquid ring pump, i.e., height times width, is substantially greater than needed by the cylinder-jacket shape of the rest of the rotor housing. Moreover, the projecting ribs form dead spaces where dirt can accumulate. Further, handling the liquid ring pump is accompanied with the risk that someone might be caught by the projecting ribs.
A liquid ring pump of the species is known from EP 0 584 106 B1. It is a multiple-flow liquid ring pump having a rotor housing which surrounds the rotor of the pump and on each of the two end sides of which a side shield is arranged. The two side shields extend beyond the rotor housing in the radial direction and each side shield has, in its projecting region, an inlet opening and an outlet opening on the side facing the other side shield. These openings are connected to each other by connecting tubes which extend parallel to the rotor housing, a suction opening being provided for a feed line and a delivery opening for a discharge line. Further connecting openings can be provided in the two lower corners, serving for the supply of operating liquid and/or for pressure compensation between the two halves of the pump. These openings are also connected via tubes that are parallel to the rotor housing. A support arm is molded on both side shields, comprising the bearings for the shaft of the rotor.
A drawback of this construction resides in the space required by the bearing disposed in the support arm and in the increased mounting requirements for the installation of the connecting tubes. The high number of projecting parts in the overall construction, such as the support arm and the connecting tubes, form nests for the accumulation of dirt which is rather difficult to remove.
It is the object of the invention to provide a liquid ring pump of the generic type which is more compact and space-saving as compared to the known prior art.
Attaining this object proceeds from the preamble of claim 1, taken in conjunction with the characterizing features thereof. Advantageous embodiments are specified in the sub-claims.
According to the invention, the outer jacket surface of each side shield is flush with the outer jacket surface of the rotor housing and the connection of the inlets and outlets as well as the connecting ports takes place via channels disposed in the rotor housing. This type of arrangement has the advantage that there are no projecting components forming nests for the accumulation of dirt, the whole aggregate consequently being cleaned more easily. Another advantage resides in that there is no need for the installation of separate connecting tubes, because they are an integral part of the rotor housing. They can for example be cast directly during manufacture. The side shields can easily be flanged on the respective end face of the rotor housing by means of through-bolts. The cross section of the rotor housing is approximately square, the side faces being curved slightly outwards and rounded where they pass into the areas of the lateral edges. The connecting channels are located in the crotches which result between the rotor housing of nearly square cross-section and the round working area, the working area being approximately centric of the rotor housing. Approximately means that the working area is either equi-axed or by some millimeters eccentric of the rotor housing. For example, the axis of the working area is eccentric of the axis of the rotor housing by five millimeters in the direction of the twelve o""clock position. Regardless of the eccentricity which correlates with the dynamic operating performance of the pump, the drill hole of the rotor housing can be displaced relative to the outer contour, preferably in the direction of the 6 o""clock position. As a result, centric of the rotor housing. Approximately means that the working area is either equi-axed or by some millimeters eccentric of the rotor housing. For example, the axis of the working area is eccentric of the axis of the rotor housing by five millimeters in the direction of the twelve o""clock position. Regardless of the eccentricity which correlates with the dynamic operating performance of the pump, the drill hole of the rotor housing can be displaced relative to the outer contour, preferably in the direction of the 6 o""clock position. As a result, the incorporated cross-sectional geometry of the upper suction and pressure channels can be made greater than the lower channels for operating liquid and dirt particles. The advantage consists in that by this measure, the cross-sectional areas can be adapted to the required volume flows and the flow rates resulting therefrom.
In known manner, one of the lower connecting ports is provided for the supply of operating liquid. According to the invention, the second connecting port is a dirt particle discharge channel provided with connecting channels which are radial of the working area. In this way, any dirt particles entrained are catapulted off by centrifugal forces in the working area and are forced by the centrifugal forces through the ports in the wall of the working area into the lengthwise discharge channel. At certain intervals, the dirt particles accumulated in the discharge channel can be removed.
So as to render the installation of the connecting lines as flexible as possible, depending on the situation of incorporation, a further development of the invention proposes to skew the end face area of the side shield that is turned away from the rotor housing and possesses the inlet and outlet opening. Preferably, this skew is in the range of 45xc2x0. This has the advantage that the supply line can be installed, saving space upwards as well as forwards. In like manner, inlet and outlet openings of equal design are formed on both side shields; they can be closed alternately so that the connection of the supply line and the delivery line may take place optionally on one of the two sides of the liquid ring pump. This principle of optional supply from one side or the other also applies to the operating liquid. Distribution to the necessary places then takes place via the connecting channel integrated in the rotor housing. For the purpose of avoiding any accumulation of dirt particles and having a compact constructional design, the invention provides the sealing as well as the bearing arrangement of the rotor shaft to be integrated in both side shields. Preferably, the sealing arrangement is disposed in a sealing housing and the bearing arrangement in a separate bearing housing. Both housings are screwed together and sealed. The advantage of this arrangement resides in that the unit of the sealing and bearing housing can be detached completely by being pulled off the rotor shaft. In this case, the rotor shaft is placed on two noses integrated in the respective cam disk. In this way it is possible to replace worn-out shaft packing rings without the entire machine having to be detached from the vehicle and dismantled completely.
Details of the invention will become apparent from the ensuing description of an exemplary embodiment of the multiple-flow liquid ring pump, taken in conjunction with the drawing, in which